Bansal Ekta, Kaur Navpreet
Department of Biochemistry, DMC&H, Ludhiana, 141001 Punjab India.
Indian J Clin Biochem. 2014 Oct;29(4):496-500. doi: 10.1007/s12291-013-0392-2. Epub 2013 Oct 12.
Traditionally Friedewald formula has been used to calculate low density lipoprotein cholesterol (LDL-C) concentration though now direct homogenous methods for its measurement are also available. Clinical guidelines recommend the use of calculated LDL-C to guide therapy because the evidence base for cholesterol management is derived almost exclusively from trials that use calculated LDL, with direct measurement of LDL-C being reserved for those patients who are non fasting or with significant hypertriglyceridemia. In this study our aim was to compare calculated and direct LDL and their variation at different cholesterol and triglyceride levels. Fasting lipid profile estimation was done on 503 outpatients in a tertiary hospital. Both direct and calculated LDL were then compared. Mean fasting direct LDL was found to be higher than calculated LDL in 87.1 % of subjects by 8.64 ± 8.35 mg/dl. This difference was seen a all levels of cholesterol and triglyceride. Using 130 mg/dl LDL cholesterol as cut off fewer subjects were classified as high risk by calculated LDL than direct LDL. In conclusion, direct LDL is higher than calculated LDL. Compared with direct measurement, the Friedewald calculation underestimates the risk for ischemic heart disease.
传统上一直使用弗瑞德瓦尔德公式来计算低密度脂蛋白胆固醇（LDL-C）浓度，不过现在也有直接匀相法用于其测量。临床指南推荐使用计算得出的LDL-C来指导治疗，因为胆固醇管理的证据几乎完全来自使用计算得出的LDL的试验，对于非空腹或有显著高甘油三酯血症的患者则采用直接测量LDL-C。在本研究中，我们的目的是比较计算得出的和直接测量的LDL及其在不同胆固醇和甘油三酯水平下的变化情况。对一家三级医院的503名门诊患者进行了空腹血脂谱评估。然后对直接测量的和计算得出的LDL进行了比较。在87.1%的受试者中，空腹直接测量的LDL平均比计算得出的LDL高8.64±8.35mg/dl。在所有胆固醇和甘油三酯水平下均观察到了这种差异。以130mg/dl的LDL胆固醇作为临界值，与直接测量的LDL相比，计算得出的LDL将更少的受试者归类为高危。总之，直接测量的LDL高于计算得出的LDL。与直接测量相比，弗瑞德瓦尔德计算低估了缺血性心脏病的风险。
